IIT JEE Practice Question and Answer
8Q: Two bus tickets from city K to L and three tickets from city K to M cost Rs. 77, but three tickets from city K to L and two tickets from city K to M cost Rs. 73. What are the fares for cities L and M from K ? 1704 05b5cc720e4d2b4197774f5e0
5b5cc720e4d2b4197774f5e0- 1Rs. 13 and Rs. 17true
- 2Rs. 17 and Rs. 19false
- 3Rs. 23 and Rs. 17false
- 4Rs. 13 and Rs. 19false
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Answer : 1. "Rs. 13 and Rs. 17"
Explanation :
Answer: A) Rs. 13 and Rs. 17 Explanation: If fares for cities L and M from K are x and y respectively, then 2x + 3y = 77 or 6x + 9y = 231...(1)3x + 2y = 73 or 6x + 4y = 146...(2) subtracting 2 from 1, we get 5y = 85 y = Rs. 17 => x = Rs. 13
Q: Consider the following statements P : Suman is brilliantQ : Suman is richR : Suman is honest The negation of the statement "Suman is brilliant and dishonest if and only if Suman is rich" can be expressed as 1) P∧~R↔Q 2) ~P∧R↔Q 3) Q↔P∧~R 4) ~Q↔P∧~R 1111 05b5cc71ee4d2b4197774f5d6
5b5cc71ee4d2b4197774f5d6- 11false
- 22false
- 33false
- 44true
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Answer : 4. "4"
Explanation :
Answer: D) 4 Explanation: Suman is brilliant and dishonest is P ∧~ RSuman is brilliant and dishonest iff suman is rich isQ ↔ (P ∧ ~ R) Negative of statement is expressed as~ (Q ↔(P ∧ ~ R)).
Q: Consider 5 independent Bernoulli’s trials each with probability of success p. If the probability of at least one failure is greater than or equal to 31/32 , then p lies in the interval ? 946 05b5cc71ee4d2b4197774f5c7
5b5cc71ee4d2b4197774f5c7- 1[1, 32]false
- 2(0, 1)false
- 3[1, 1/2]true
- 4(1, 1/2]false
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Answer : 3. "[1, 1/2]"
Explanation :
Answer: C) [1, 1/2] Explanation: Probability of atleast one failure= 1 - no failure > 31/32= 1 - P5 > 31/32= P5<1/32= p < 1/2Also p > 0Hence p lies in [0,1/2].
Q: A man saves Rs. 200 in each of the first three months of his service. In each of the subsequent months his saving increases by Rs. 40 more than the saving of immediately previous month. His total saving from the start of service will be Rs. 11040 after ? 1465 05b5cc71ee4d2b4197774f5b8
5b5cc71ee4d2b4197774f5b8- 119 monthsfalse
- 221 monthstrue
- 318 monthsfalse
- 420 monthsfalse
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Answer : 2. "21 months"
Explanation :
Answer: B) 21 months Explanation: Total savings = 200 + 200 + 200 + 240 + 280 + ... to n months = 11040 = 120 + 80 + 160 + 40 + 200 + 240 + ....n terms= 40 + 80 + 120 + 160 + 200 + 240 + ...n terms= n/2[2a + (n-1)d] + 80 + 40 = 11040= n/2[240 + (n-1)40] = 10920= n[6+n-1] = 546= n[n+5] = 546n = 21
Q: Three friends had dinner at a restaurant. When the bill was received, Akshitha paid 2/3 as much as Veena paid and Veena paid 1/2 as much as Lasya paid. What fraction of the bill did Veena pay ? 1294 05b5cc71ee4d2b4197774f5ae
5b5cc71ee4d2b4197774f5ae- 111/3false
- 22/13false
- 33/11true
- 413/4false
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Answer : 3. "3/11"
Explanation :
Answer: C) 3/11 Explanation: Let Veena paid x,so Akshitha paid 2x/3 , and Lasya paid 2x,So total bill paid is given byx+(2x/3) +2x = 1, we geti.e. x = 3/11
Q: A bird lover was asked how many birds he had in the basket. He replied that there were all parrots but six, all pigeons but six, and all koel but six. How many birds he had in the basket in all ? 2697 05b5cc71ee4d2b4197774f5a9
5b5cc71ee4d2b4197774f5a9- 18false
- 218false
- 39true
- 410false
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Answer : 3. "9"
Explanation :
Answer: C) 9 Explanation: There were all parrots but six means that six birds were not parrots but only pigeons and koels. Similarly, number of parrots + number of koels = 6 and number of parrots + number of pigeons = 6. This is possible when there are 3 parrots, 3 pigeons and 3 koels i.e. 9 birds in all.
Q: An intelligent boy is doing a jigsaw with 275 pieces. Each day that he fits pieces together there are fewer pieces left, and it is reasonable to assume that he fits more pieces each day because the number left to sort out diminishes progressively. Hence he is able to fit an extra piece as each day goes by. On the first day he fits 20 pieces. How many days does it take for him to complete the puzzle ? 2084 05b5cc71ee4d2b4197774f59a
5b5cc71ee4d2b4197774f59a- 111 daystrue
- 215 daysfalse
- 313 daysfalse
- 416 daysfalse
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Answer : 1. "11 days"
Explanation :
Answer: A) 11 days Explanation: Let 'n' number of days it take to complete. we know that sum of n number= n/2[2a+(n-1)d]where a=20,d=1;n/2[2x20+(n-1)1]=275n[n+39]=550n2 + 39n - 550 = 0 n2+ 50n - 11n - 550 = 0(n-11) (n-50) = 0n-11 = 0;n = 11(Days).
Q: Ravi and Ramu are partners in a business.Ravi contributes 1/6 of the capital for 16 months and Ramu received 2/3 of the profit. For how long Ramu's money was used ? 1681 05b5cc71ee4d2b4197774f590
5b5cc71ee4d2b4197774f590- 111 monthsfalse
- 210 monthsfalse
- 39 monthsfalse
- 48 monthstrue
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Answer : 4. "8 months"
Explanation :
Answer: D) 8 months Explanation: Let the total Profit be Z.Ramu's profit share is 2/3 of profit (i.e 2Z/3)Ravi's profit is (Z-2Z/3) =Z/3Hence the profit ratio is , Ravi : Ramu = Z/3 : 2Z/3 = 1:2 Let total Capital be Rs.X and Ramu has contributed for Y months.Since Ramu's profit share is 2/3, his invest share will be 2/3 in capital. Ravi's invest for 16 months / Ramu's invest for Y months = Ravi's profit share / Ramu's profit sharei.e. (X/6 x 16) / (2X/3 x Y) = 1/2 Solving the above equation, we get Y = 8.So Ramu's money has been used for 8 months.